Here I will explain how to calculate age of person from date of
birth and regular expression for mm/dd/yyyy format using JavaScript.

Description:

In some situation we need to display age of person based on date
of birth .In that situation we can calculate age of person using JavaScript by
comparing present date and date of birth as shown below. Here I have a one
textbox every time I need to validate that data whether user enter valid data
or not if the date not in mm/dd/yyyy format or not.